<html>
<body>
 <p>
	Reads from the standard input or from a specified input file and compares
	adjacent lines, writing one copy  of each input line on the output. The
	second and succeeding copies of repeated adjacent input lines are not 
	written to the output.
 </p>
 <p>
	Note that repeated non-adjacent lines in the input are only detected
	with the --global or -g option. In other words, unique output lines
	are guaranteed only if either (a) the --global or -g option is
	specified, or (b) the input lines are sorted.
 </p>
 </body>
</html>